DISCUSSION
This manuscript reports the combined implantation technique (S-ICD+AAE) that we have been using in a satisfactory manner at our centers in very high-risk patients over the last 2+ years. To our knowledge, this is the first report of the combined use of an AAE and S-ICD system in patients at very high-risk of infection. Although not being explicitly branded for the S-ICD system, the use of an AAE guarding a S-ICD device was completely feasible and safe in our cohort. Only little processing of the current commercially available AAE was needed, without difficult or lengthy maneuvers that may disrupt the routine or the normal workflow of a device laboratory. Procedural times and peri-procedural complication rates were not impacted by this practice, that does not have a learning curve for proceduralists accustomed by both components of this procedure. Albeit the cohort being at very high-risk of infection, no device related infections were observed at one-year and only a single, conservatively manageable, pocket infection was observed during the entire follow-up. These authors stand against a routine use of this combined procedure for all patients undergoing S-ICD placement. A careful patient selection and a patient-tailored assessment are needed to maximize the benefits associated with this approach. Nonetheless, it is our belief that this approach might benefit a niche of very high-risk of infection patients for which only limited data is available in the currently published major randomized trials8,9.Figure 1 reports the decisional flow algorithm we have been using at our institution to select patients potentially suitable for this combined approach.
A clinical and economical net benefit with the use of an AAE has been reported in selected patients with TV-ICD and, although previous reports failed to describe patients at a very high-risk of infection9, data suggesting that AAE provides value for the healthcare system by reducing the incidence of CIED infection could be easily extended to the S-ICD10. If it is true that infective device-associated complications in patients implanted with an S-ICD system carry a lower mortality burden, being the management of those achieved with less invasive and less risky procedures, they cause patient discomfort and hospitalization for potential re-intervention is often required11. This may not pose a severe threat in a fit and young patient, but these patients at a very high-risk of infections are often frail, in a compromised systemic condition, and suffer from multiple sever comorbidities. Therefore, re-hospitalizations and re-interventions carry a different clinical impact in such a population, who often also shows a high arrhythmic burden (44% received an appropriate shock during follow-up) and cannot overlook the need for an ICD. This combined procedure is exactly aimed at minimizing re-hospitalizations in very high-risk patients, while helping to maximize the net benefit that the S-ICD may offer in specific clinical settings. Indeed, although re-hospitalization costs associated with the management of S-ICD related complications may be lower than what is observed in TV-ICDs, the device itself is currently much more expensive (currently billed around 2.5-3x times its TV-ICD counterpart in our country) and the deployment of an AAE may help avoiding expensive system replacement, reducing the overall costs for the healthcare system.